sys/dev/iicbus/if_ic.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1998, 2001 Nicolas Souchu
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 /*
  33  * I2C bus IP driver
  34  */
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/mbuf.h>
  39 #include <sys/socket.h>
  40 #include <sys/filio.h>
  41 #include <sys/sockio.h>
  42 #include <sys/kernel.h>
  43 #include <sys/lock.h>
  44 #include <sys/module.h>
  45 #include <sys/mutex.h>
  46 #include <sys/bus.h>
  47 #include <sys/time.h>
  48 #include <sys/malloc.h>
  49
  50 #include <net/if.h>
  51 #include <net/if_var.h>
  52 #include <net/if_types.h>
  53 #include <net/netisr.h>
  54
  55 #include <net/route.h>
  56 #include <netinet/in.h>
  57 #include <netinet/in_systm.h>
  58 #include <netinet/in_var.h>
  59 #include <netinet/ip.h>
  60 #include <netinet/if_ether.h>
  61
  62 #include <net/bpf.h>
  63
  64 #include <dev/iicbus/iiconf.h>
  65 #include <dev/iicbus/iicbus.h>
  66
  67 #include "iicbus_if.h"
  68
  69 #define PCF_MASTER_ADDRESS 0xaa
  70
  71 #define ICHDRLEN        sizeof(u_int32_t)
  72 #define ICMTU           1500            /* default mtu */
  73
  74 struct ic_softc {
  75         struct ifnet *ic_ifp;
  76         device_t ic_dev;
  77
  78         u_char ic_addr;                 /* peer I2C address */
  79
  80         int ic_flags;
  81
  82         char *ic_obuf;
  83         char *ic_ifbuf;
  84         char *ic_cp;
  85
  86         int ic_xfercnt;
  87
  88         int ic_iferrs;
  89
  90         struct mtx ic_lock;
  91 };
  92
  93 #define IC_SENDING              0x0001
  94 #define IC_OBUF_BUSY            0x0002
  95 #define IC_IFBUF_BUSY           0x0004
  96 #define IC_BUFFERS_BUSY         (IC_OBUF_BUSY | IC_IFBUF_BUSY)
  97 #define IC_BUFFER_WAITER        0x0004
  98
  99 static devclass_t ic_devclass;
 100
 101 static int icprobe(device_t);
 102 static int icattach(device_t);
 103
 104 static int icioctl(struct ifnet *, u_long, caddr_t);
 105 static int icoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
 106                struct route *);
 107
 108 static int icintr(device_t, int, char *);
 109
 110 static device_method_t ic_methods[] = {
 111         /* device interface */
 112         DEVMETHOD(device_probe,         icprobe),
 113         DEVMETHOD(device_attach,        icattach),
 114
 115         /* iicbus interface */
 116         DEVMETHOD(iicbus_intr,          icintr),
 117
 118         { 0, 0 }
 119 };
 120
 121 static driver_t ic_driver = {
 122         "ic",
 123         ic_methods,
 124         sizeof(struct ic_softc),
 125 };
 126
 127 static void
 128 ic_alloc_buffers(struct ic_softc *sc, int mtu)
 129 {
 130         char *obuf, *ifbuf;
 131
 132         obuf = malloc(mtu + ICHDRLEN, M_DEVBUF, M_WAITOK);
 133         ifbuf = malloc(mtu + ICHDRLEN, M_DEVBUF, M_WAITOK);
 134
 135         mtx_lock(&sc->ic_lock);
 136         while (sc->ic_flags & IC_BUFFERS_BUSY) {
 137                 sc->ic_flags |= IC_BUFFER_WAITER;
 138                 mtx_sleep(sc, &sc->ic_lock, 0, "icalloc", 0);
 139                 sc->ic_flags &= ~IC_BUFFER_WAITER;
 140         }
 141
 142         free(sc->ic_obuf, M_DEVBUF);
 143         free(sc->ic_ifbuf, M_DEVBUF);
 144         sc->ic_obuf = obuf;
 145         sc->ic_ifbuf = ifbuf;
 146         sc->ic_ifp->if_mtu = mtu;
 147         mtx_unlock(&sc->ic_lock);
 148 }
 149
 150 /*
 151  * icprobe()
 152  */
 153 static int
 154 icprobe(device_t dev)
 155 {
 156         return (BUS_PROBE_NOWILDCARD);
 157 }
 158
 159 /*
 160  * icattach()
 161  */
 162 static int
 163 icattach(device_t dev)
 164 {
 165         struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
 166         struct ifnet *ifp;
 167
 168         ifp = sc->ic_ifp = if_alloc(IFT_PARA);
 169         if (ifp == NULL)
 170                 return (ENOSPC);
 171
 172         mtx_init(&sc->ic_lock, device_get_nameunit(dev), MTX_NETWORK_LOCK,
 173             MTX_DEF);
 174         sc->ic_addr = PCF_MASTER_ADDRESS;       /* XXX only PCF masters */
 175         sc->ic_dev = dev;
 176
 177         ifp->if_softc = sc;
 178         if_initname(ifp, device_get_name(dev), device_get_unit(dev));
 179         ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
 180         ifp->if_ioctl = icioctl;
 181         ifp->if_output = icoutput;
 182         ifp->if_hdrlen = 0;
 183         ifp->if_addrlen = 0;
 184         ifp->if_snd.ifq_maxlen = ifqmaxlen;
 185
 186         ic_alloc_buffers(sc, ICMTU);
 187
 188         if_attach(ifp);
 189
 190         bpfattach(ifp, DLT_NULL, ICHDRLEN);
 191
 192         return (0);
 193 }
 194
 195 /*
 196  * iciotcl()
 197  */
 198 static int
 199 icioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 200 {
 201         struct ic_softc *sc = ifp->if_softc;
 202         device_t icdev = sc->ic_dev;
 203         device_t parent = device_get_parent(icdev);
 204         struct ifaddr *ifa = (struct ifaddr *)data;
 205         struct ifreq *ifr = (struct ifreq *)data;
 206         int error;
 207
 208         switch (cmd) {
 209
 210         case SIOCAIFADDR:
 211         case SIOCSIFADDR:
 212                 if (ifa->ifa_addr->sa_family != AF_INET)
 213                         return (EAFNOSUPPORT);
 214                 mtx_lock(&sc->ic_lock);
 215                 ifp->if_flags |= IFF_UP;
 216                 goto locked;
 217         case SIOCSIFFLAGS:
 218                 mtx_lock(&sc->ic_lock);
 219         locked:
 220                 if ((!(ifp->if_flags & IFF_UP)) &&
 221                     (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
 222
 223                         /* XXX disable PCF */
 224                         ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 225                         mtx_unlock(&sc->ic_lock);
 226
 227                         /* IFF_UP is not set, try to release the bus anyway */
 228                         iicbus_release_bus(parent, icdev);
 229                         break;
 230                 }
 231                 if (((ifp->if_flags & IFF_UP)) &&
 232                     (!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
 233                         mtx_unlock(&sc->ic_lock);
 234                         if ((error = iicbus_request_bus(parent, icdev,
 235                             IIC_WAIT | IIC_INTR)))
 236                                 return (error);
 237                         mtx_lock(&sc->ic_lock);
 238                         iicbus_reset(parent, IIC_FASTEST, 0, NULL);
 239                         ifp->if_drv_flags |= IFF_DRV_RUNNING;
 240                 }
 241                 mtx_unlock(&sc->ic_lock);
 242                 break;
 243
 244         case SIOCSIFMTU:
 245                 ic_alloc_buffers(sc, ifr->ifr_mtu);
 246                 break;
 247
 248         case SIOCGIFMTU:
 249                 mtx_lock(&sc->ic_lock);
 250                 ifr->ifr_mtu = sc->ic_ifp->if_mtu;
 251                 mtx_unlock(&sc->ic_lock);
 252                 break;
 253
 254         case SIOCADDMULTI:
 255         case SIOCDELMULTI:
 256                 if (ifr == NULL)
 257                         return (EAFNOSUPPORT);          /* XXX */
 258                 switch (ifr->ifr_addr.sa_family) {
 259                 case AF_INET:
 260                         break;
 261                 default:
 262                         return (EAFNOSUPPORT);
 263                 }
 264                 break;
 265         default:
 266                 return (EINVAL);
 267         }
 268         return (0);
 269 }
 270
 271 /*
 272  * icintr()
 273  */
 274 static int
 275 icintr(device_t dev, int event, char *ptr)
 276 {
 277         struct ic_softc *sc = (struct ic_softc *)device_get_softc(dev);
 278         struct mbuf *top;
 279         int len;
 280
 281         mtx_lock(&sc->ic_lock);
 282
 283         switch (event) {
 284
 285         case INTR_GENERAL:
 286         case INTR_START:
 287                 sc->ic_cp = sc->ic_ifbuf;
 288                 sc->ic_xfercnt = 0;
 289                 sc->ic_flags |= IC_IFBUF_BUSY;
 290                 break;
 291
 292         case INTR_STOP:
 293
 294                 /* if any error occurred during transfert,
 295                  * drop the packet */
 296                 sc->ic_flags &= ~IC_IFBUF_BUSY;
 297                 if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
 298                     IC_BUFFER_WAITER)
 299                         wakeup(&sc);
 300                 if (sc->ic_iferrs)
 301                         goto err;
 302                 if ((len = sc->ic_xfercnt) == 0)
 303                         break;                                  /* ignore */
 304                 if (len <= ICHDRLEN)
 305                         goto err;
 306                 len -= ICHDRLEN;
 307                 if_inc_counter(sc->ic_ifp, IFCOUNTER_IPACKETS, 1);
 308                 if_inc_counter(sc->ic_ifp, IFCOUNTER_IBYTES, len);
 309                 BPF_TAP(sc->ic_ifp, sc->ic_ifbuf, len + ICHDRLEN);
 310                 top = m_devget(sc->ic_ifbuf + ICHDRLEN, len, 0, sc->ic_ifp, 0);
 311                 if (top) {
 312                         struct epoch_tracker et;
 313
 314                         mtx_unlock(&sc->ic_lock);
 315                         M_SETFIB(top, sc->ic_ifp->if_fib);
 316                         NET_EPOCH_ENTER(et);
 317                         netisr_dispatch(NETISR_IP, top);
 318                         NET_EPOCH_EXIT(et);
 319                         mtx_lock(&sc->ic_lock);
 320                 }
 321                 break;
 322         err:
 323                 if_printf(sc->ic_ifp, "errors (%d)!\n", sc->ic_iferrs);
 324                 sc->ic_iferrs = 0;                      /* reset error count */
 325                 if_inc_counter(sc->ic_ifp, IFCOUNTER_IERRORS, 1);
 326                 break;
 327
 328         case INTR_RECEIVE:
 329                 if (sc->ic_xfercnt >= sc->ic_ifp->if_mtu + ICHDRLEN) {
 330                         sc->ic_iferrs++;
 331                 } else {
 332                         *sc->ic_cp++ = *ptr;
 333                         sc->ic_xfercnt++;
 334                 }
 335                 break;
 336
 337         case INTR_NOACK:                        /* xfer terminated by master */
 338                 break;
 339
 340         case INTR_TRANSMIT:
 341                 *ptr = 0xff;                                    /* XXX */
 342                 break;
 343
 344         case INTR_ERROR:
 345                 sc->ic_iferrs++;
 346                 break;
 347
 348         default:
 349                 panic("%s: unknown event (%d)!", __func__, event);
 350         }
 351
 352         mtx_unlock(&sc->ic_lock);
 353         return (0);
 354 }
 355
 356 /*
 357  * icoutput()
 358  */
 359 static int
 360 icoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
 361     struct route *ro)
 362 {
 363         struct ic_softc *sc = ifp->if_softc;
 364         device_t icdev = sc->ic_dev;
 365         device_t parent = device_get_parent(icdev);
 366         int len, sent;
 367         struct mbuf *mm;
 368         u_char *cp;
 369         u_int32_t hdr;
 370
 371         /* BPF writes need to be handled specially. */
 372         if (dst->sa_family == AF_UNSPEC)
 373                 bcopy(dst->sa_data, &hdr, sizeof(hdr));
 374         else
 375                 hdr = dst->sa_family;
 376
 377         mtx_lock(&sc->ic_lock);
 378         ifp->if_drv_flags |= IFF_DRV_RUNNING;
 379
 380         /* already sending? */
 381         if (sc->ic_flags & IC_SENDING) {
 382                 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
 383                 goto error;
 384         }
 385
 386         /* insert header */
 387         bcopy ((char *)&hdr, sc->ic_obuf, ICHDRLEN);
 388
 389         cp = sc->ic_obuf + ICHDRLEN;
 390         len = 0;
 391         mm = m;
 392         do {
 393                 if (len + mm->m_len > sc->ic_ifp->if_mtu) {
 394                         /* packet too large */
 395                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
 396                         goto error;
 397                 }
 398
 399                 bcopy(mtod(mm,char *), cp, mm->m_len);
 400                 cp += mm->m_len;
 401                 len += mm->m_len;
 402
 403         } while ((mm = mm->m_next));
 404
 405         BPF_MTAP2(ifp, &hdr, sizeof(hdr), m);
 406
 407         sc->ic_flags |= (IC_SENDING | IC_OBUF_BUSY);
 408
 409         m_freem(m);
 410         mtx_unlock(&sc->ic_lock);
 411
 412         /* send the packet */
 413         if (iicbus_block_write(parent, sc->ic_addr, sc->ic_obuf,
 414                                 len + ICHDRLEN, &sent))
 415
 416                 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
 417         else {
 418                 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
 419                 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
 420         }
 421
 422         mtx_lock(&sc->ic_lock);
 423         sc->ic_flags &= ~(IC_SENDING | IC_OBUF_BUSY);
 424         if ((sc->ic_flags & (IC_BUFFERS_BUSY | IC_BUFFER_WAITER)) ==
 425             IC_BUFFER_WAITER)
 426                 wakeup(&sc);
 427         mtx_unlock(&sc->ic_lock);
 428
 429         return (0);
 430
 431 error:
 432         m_freem(m);
 433         mtx_unlock(&sc->ic_lock);
 434
 435         return(0);
 436 }
 437
 438 DRIVER_MODULE(ic, iicbus, ic_driver, ic_devclass, 0, 0);
 439 MODULE_DEPEND(ic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
 440 MODULE_VERSION(ic, 1);